Ruby

strftime.c: format in String

• strftime.c (rb_strftime_with_timespec): append formatted results
  to the given string with expanding, and also deal with NUL chars.
• strftime.c (rb_strftime, rb_strftime_timespec): return formatted
  string, not the length put in the given buffer.
• time.c (rb_strftime_alloc): no longer needs to retry with
  reallocating buffers.
• time.c (time_strftime): no longer needs to split by NUL chars.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@54236 b2dd03c8-39d4-4d8f-98ff-823fe69b080e